IBM PCjr Hardware Maintenance And Service page 79

You should have already replaced the keyboard.
1. Replace the infra-red receiver.
2. The original keyboard is good. Set it in front of the
system unit instead of using the replacement
keyboard.
3. Perform advanced POST.
64KB
ERROR
2000
DID ADVANCED POST ERROR "2000" OR "22XX"
APPEAR?
The problem has been corrected. Repeat
advanced POST and the advanced tests to
ensure that the IBM PCjr is operating
correctly.
Keyboard 3-300-3